Electrostatically actuated display panel

ABSTRACT

An electrostatically actuated character generating display panel is disclosed. The display panel embodies one or more flexible membrane sections disposed in a predetermined pattern in an electric field generated between a transparent window and a closely spaced parallel support substrate. By electrically charging the individual membrane sections, electrostatic forces are generated which displace the charged sections either to or away from the window. The space between the window and the substrate is filled with a contrasting colored, high dielectric opaque fluid which normally occludes the membrane sections when they are displaced towards the substrate. When the electrostatic forces displace the membrane sections against the window, the membrane displaces the opaque fluid and the contacting portion of the membrane section becomes visible through the window. Selectively charging individual membrane sections in the pattern, indicative of the character to be formed, selectively displaces the charged membrane sections against the window and the desired character is visually formed. Alternatively, a message imprinted upon a single segment can similarly be made to appear or disappear.

j United States 11 3,924,228

Goodrich 51 Dec. 2. 1975 [541 ELECTROSTATICALLY ACTUATED [57] ABSTRACTDISPLAY PANEL UNITED STATES PATENTS 11/1956 Marcy 340/378 R 12/1964Cunnien... 340/366 R 10/1965 Jacob... 340/366 R 4/1968 Kushner eta.340/324 R 1/1971 Banks et a1. 350/161 5/1974 Goodrich 340/324 R 7/1974Passien 340/378 R Primary ExaminerDavid L. Trafton Attorney. Agent. orFirmJames R. lgnatowski CONT/Q04 LOG/C An clectrostatically actuatedcharacter generating display panel is disclosed. The display panelembodies one or more flexible membrane sections disposed in apredetermined pattern in an electric field generated between atransparent window and a closely spaced parallel support substrate. Byelectrically charging the individual membrane sections. electrostaticforces are generated which displace the charged sections either to oraway from the window. The space between the window and the substrate isfilled with a contrasting colored. high dielectric opaque fluid whichnormally occludes the membrane sections when they are displaced towardsthe substrate. When the electrostatic t'orces displace the membranesections against the window. the membrane displaces the opaque fluid andthe contacting portion of the membrane section becomes visible throughthe window. Selectively charging individual membrane sections in thepattern. indicative of the character to be formed. selectively displacesthe charged membrane sections against the window and the desiredcharacter is visually formed. Alternatively. a message imprinted upon asingle segment can similarly be made to appear or disappear.

38 Claims. 9 Drawing Figures CHARACTER m/puT US. Patent Dec. 2, 1975Sheet 1 01 4 3,924,228

(O/VTROL 406/6 CHAR/1675f? P 7' FIGI onvu

FIG-2 US. Patant Dec. 2, 1975 Sheet 2 014 3,924,228

US. atent Dec. 2, 1975 Sheet 3 of4 3,924,228

FIG.6 l

LOG/C CONTROL 106/6 CONTROL US. Patent Dec. 2, 1975 Sheet 4 of43,924,228

FIG. 8

5 1 W BRAKE/FLU/D LOW T ELECTROSTATICALLY ACTUATED DISPLAY PANELBACKGROUND OF THE INVENTION 1. Field of the Invention The invention isrelated to the field of visual communications and, in particular, topassive display panel producing alpha numerical characters byelectrostatically moving selected flexible membrane sections against thesurface of a transparent window displacing an opaque fluid disposedtherebetween and forming visible characters.

2. Prior Art Display panels may be roughly categorized as luminous orpassive dependent upon whether they are self luminous or require ambientlight to relay the information to the recipient. Luminous displaypanels, such as cathode ray tubes, arrays of light emitting diodes, andplasma panels have found wide acceptance in both industry and generalpublic use. The deficiency of luminous display panels is the tendency ofthe information displayed to be washed out, and even lost under intenseambient illumination. In contrast, passive display panels transmit theinformation to the recipient by means of reflected ambient light andvisibility increases with increased ambient illumination. Passivedisplay panels have practical application where the ambient illuminationmay vary from intense daylight to subdued conditions.

Passive display panels range in form from the time honored score boardsfound in baseball parks to the more recent electronically activatedliquid crystal displays and includes various types of panels in whichthe information is made visible by displacing an opaque fluid fillingthe space between a transparent window and the desired information. Thedisplacement of the opaque fluid is generally accomplished by moving theinformation bearing member into physical contact with the window. Thephysical contact displaces the fluid from between the window and memberand the information, otherwise occluded by the opaque fluid, becomesvisible. The prior art teaches the displacement of information orcharacter bearing members by mechanical, pneumatic, fluidic andelectromagnetic forces. G. A. Wearham, in U.S. Pat. Nos. 1,780,733 and1,782,328 teaches the displacement of the member by both mechanical andfluidic means. J. M. Cunnien, in U.S. Pat. No. 3,162,849 introduces theconcept of using electromagnetic means for moving the character bearingmember. These early displays are confined to simple on/off devices andwere incapable of generating individual characters of various forms inany one given location on the face of the panel.

Many of the present applications for display panels require highcharacter densities which may be changed upon command and the simpleon/off configurations of the prior art are incapable of meeting thisrequirement.

An initial attempt to overcome this problem is disclosed in my earlierU.S. Pat. No. 3,812,490, Flexible Membrane Display Panel for GeneratingCharacters Visible in Ambient Light. This device uses a magnetizedflexible membrane disposed in an opaque fluid a short distance from awindow. The membrane is selectively deflected to form the desiredcharacters by a matrix of small electromagnets formed on a magneticallysusceptible substrate disposed behind the magnetized membrane on theside opposite the window. This electromagnetically activated displaypanel represents one solution to the problem.

The prior art further reveals that others have attempted to useelectrostatic forces to activate passive display panels. W. R. Aiken inU.S. Pat. No. 3,304,549 discloses a Composite Signaling Device" in whicha matrix of hinged vanes representing various segments of a characterare displaced by electrostatic forces from a horizontal to verticalposition making them visible through a transparent window. In analternate configuration, as disclosed by Dahms et a1, a hinged vane orflag is systematically deflected to one or the other side of V-shapedgrooves to form the desired character. The opposite sides of the vanesand opposite sides of the V-shaped grooves have the same contrastingcolors. The vanes are arranged so that each face of vane has the samecolor as the adjacent face of the groove, so that when the vane isdeflected to one side, the exposed face of the vane and the exposedsurface of the V groove have the same color, and when the vane isdeflected to the other side, the opposite side of the vane and the otherface of the groove are exposed, displaying the contrasting color. Inboth of these types of displays, the vane is required to move through aconsiderable distance and relatively high electrostatic voltages arerequired. Electrostatic deflection of a reflective membrane for lightmodulators has also been used with large screen television displays.Typical examples of such devices are disclosed by P. Kendall, Jr. et a1,U.S. Pat. No. 3,796,480, as well as my own U.S. Pat. No. 3,746,785.

SUMMARY OF THE INVENTION The invention is an electrostatically actuatedpassive display panel. The panel comprises a plurality of electricallyisolated conductive membrane sections systematically disposed along thesurface of a support structure in a predetermined pattern. A transparentwindow having an electrically conductive internal surface is disposedparallel to the support structure and proximate the conductive membranesections so that a distance of approximately 0.01 centimeter separatesthe window from the adjacent surfaces of the membrane section. The spacebetween the window and the membrane sections is filled with a lowconductivity, high dielectric constant, colored fluid having sufficientopacity to occlude the membrane section when viewed through the window.One end of each membrane section is fixedly attached to the supportstructure and the opposite end is free to move under the influence ofinternally generated electrostatic forces. Under the influence ofelectrostatic forces, the free ends of the membrane sections contact theinner surface of the transparent window. The free end of each membranesection has a region imprinted with a color contrasting to the color ofthe fluid so that when the free end is in contact with the window, thecontrasting color of the imprinted region is visible therethrough. Meansare further provided for generating an electric field between theconductive surface disposed along the inner surface of the window andthe support structure and for individually conducting an electricalcharge to each electrically isolated membrane section. Selectivelycharging individual membrane sections with electrical signals, having apolarity the same as that applied to the support structure, willgenerate an electrostatic field and therefor an electrostatic forcebetween the window and the charged membrane sections. The attractiveelectrostatic force urges the free ends of the charged membrane sectionsaway from the support structure and into contact with the window,displacing the opaque fluid and rendering the region imprinted with thecontrasting color to be visible. Reversing the polarity of the charge onthe individual membrane sections so that it will have the same charge ason the window will return their free ends to their original positionalong the support substrate.

In a preferred embodiment, the membrane sections are arranged in thefamiliar seven bar alpha numerical pattern, including an eighth membranesection for generating a period or decimal point. The invention may beembodied in an elementary form containing only a single membrane sectionwith an imprinted message or a single alpha numerical pattern. Thedisplay may also take more complex forms having a plurality of patternsarranged in linear or in two dimensional matrices. The electrical powerand potentials required for activation of the electrostaticallyactivated display panel are well within the state of the art of solidstate logic and switch ing devices, and may be either AC or DC.

The object of the invention is a passive electrostatically activateddisplay panel compatible with state of the art logic circuitry andcomponents having a high character density. A further object of theinvention is a multiple character passive display panel relativelysimple and inexpensive to make. Still another objective of the inventionis a multiple character passive display panel using no exotic orexpensive components or manufacturing techniques. Another object is adisplay panel which may be matrix addressed or multiplexed. These andother objectives will become evident from a reading of the followingdetailed description of the preferred embodiment.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an exaggerated cross sectionview of a preferred embodiment of the electrostatically activateddisplay panel to show the individual elements and con struction details.

FIG. 2 is a plan view of the membrane sections arranged in the familarseven bar alpha numerical pattern.

FIG. 3 is a plan view of an alternate embodiment of the composite basehaving the leads to the individual membrane sections along a commonedge.

FIG. 4 is a cross section of the alternate embodiment shown in FIG. 3.

FIG. 5 is a cut away perspective illustrating a multi characterembodiment of the display panel.

FIG. 6 is a plan view of an alternate embodiment of a compositesubstrate for a display panel capable of being multiplexed.

FIG. 7 is a plan view of an alternate embodiment of a compositesubstrate for a panel capable of being matrix addressed.

FIG. 8 is a plan view of a composite base having a single membranesection with a printed message.

FIG. 9 is a plan view of a composite base having an alternateconfiguration for the membrane sections.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT The details of thepreferred embodiment of the electrostatically activated membrane panelis discussed with reference to the exaggerated cross sectional view ofFIG. 1. This cross sectional view shows the basic elements and thesephysical relationships to each other.

a: Referring to FIG. 1, the body of the display panel comprises acomposite transparent window 10, a composite membrane support base 12and a spacer body 14. The composite window 10. composite base 12 andspacer body 14 form a structure having an internal cavity completelyfilled with a low conductivity opaque fluid 16. The composite windowcomprises a window 18, such as glass or any other suitable transparentmaterial and has a transparent conductive coating of any type known inthe art which is applied along the inner surface of the window 18. Thetransparent conductive coating 20, for example, may be a tin oxidecoating, such as the commercially available NESA coating or atransparent vapor-deposited metalic film. The conductive coating 18 isfurther overlaid with an insulation material 22. When the conductivityof the insulating material 22 is approximately equal to the conductivityof the opaque fluid 16, the insulating material may be in the form of acontinuous layer disposed over the conductive coating 20. However, whenthe conductivity of the insulating material is substantially less thanthat of the opaque fluid, the insulating material may be disposed overthe conductive coating 20 in the form of a plurality of isolated islandssuch as would be obtained by evaporating silicon monoxide or otherinsulating material through a fine mesh screen. The spacing between theisolated islands being sufficiently small to prevent the conductivedeflectable membrane sections 28 from contacting the conductive coating20 between the islands.

The composite membrane support base 12 in the illustrated embodiment ofFIG. 1 comprises a metal plate 24 overlaid with an insulating material26. Like the composite window, when the conductivity of the insulatingmaterial 26 is approximately equal to the conductivity of the opaquefluid 16, the insulating material may be in the form of a thincontinuous layer disposed over the internal surface of the metal plate24. However, when the conductivity of the insulating material issubstantially less than the conductivity of the opaque fluid, theinsulating material may be disposed along the surface of the metal platein the form of a plu rality of isolated islands. The islandconfiguration of the insulating material on the composite window andcomposite base permits the opaque fluid, having the higher conductivity,to be in electrical contact with conductive surfaces of the window andthe base and enhances the establishment of a more uniform electricalfield therebetween. In alternate embodiments, to be discussedhereinafter, the composite base 12 may be made from an insulatingmaterial with a conductive coating disposed along the surface thereof.Attached to the insulating material 26 are a plurality of electricallyisolated deflectable membrane sections 28 which will be discussed indetail with reference to FIG. 2. Electrical contact to each individualmembrane section 28 is made by a like plurality of conductor elements,illustrated as pins 30 making electrical contact with each membranesection and passing through the metal plate 24- and insulating material26 to the external surface of the display panel. By this means eachmembrane section 28 may be individually charged by an electricalpotential applied to the associated pin 30. Insulator grommets 32 areprovided for electrical isolation between each pin 30 and the metalplate 24.

The spacer body 14 is made from an insulating material and provides acircumferential fluid seal between the composite window 10 and thecomposite support plate 12. The thickness of the spacer body 14 isselected so that the separation between the inner surface 34 ofinsulation layer 22 and the upper surface 36 of the membrane sections28, indicated as dimension is approximately 0.01 centimeter.

The opaque fluid 16 is a high dielectric constant, low conductivity,colored fluid such as ethyl acetate, colored with a commercial oilsoluble dye.

Electrical power is applied to the transparent conductive layer 20 andthe metal plate from a source of electrical power illustrated as battery38. Electrical power is also applied to each of the membrane sections 28via pins 30 and connecting leads from a control logic circuit 40. Thecontrol logic circuit 40 has an input indicative of the character to beformed. This input may be a manual input from a keyboard, or anelectrical signal from an external source (not shown). The various typesof inputs and the manner in which they are generated are well known inthe art and need not be discussed for an understanding of the invention.The control logic circuit may be powered from the same source as thedisplay panel, as shown, or may be powered by an independent electricalsource. The control logic circuit is of conventional form and inresponse to an input indicative of a specific character outputselectrical signals on the leads connected to the pins 30. In thepreferred embodiment, the output sig nals from the control logic arebipolar electrical signals having either a magnitude and polarity thesame as that applied to the transparent conductive layer 20 or themagnitude and polarity the same as that applied to the metal plate 24from the electrical power source.

The details of the membane sections 28 are discussed with reference toFIG. 2. This illustrated embodiment comprises eight electricallyisolated membrane sections 28. Seven of the sections are arranged todefine the elements of a typical seven bar alpha numerical character andthe eighth section is a period or decimal point. The use of this patternto generate both letters and numerals is well known and need not befurther discussed. The membrane sections 28 may be a thin metal foilsuch as 2 um thick aluminum foil or made from a thin sheet or film of asuitable plastic material, as polyester or polyvinyl chloride, heavilyloaded with conducting particles, such as carbon black, so that eachsection is electrically conductive and assumes a common electricalpotential when charged. Alternatively, the plastic film may bemetalized, using conventional metal deposition methods, such as vapordeposition to provide the desired electrical conductivity. In caseswhere the electrical charge leaking from the individual sections mayotherwise cause life limiting electrolysis of the opaque fluid 16, athin insulating layer may be deposited over the conductive surfaces ofthe individ ual membrane sections as a barrier to electronic exchange toions in the fluid.

Each membrane section 28, forming the alpha numerical character, iscomprised of three regions, as il lustrated. The first region,arbitrarily defined by the crosshatched area, is electrical contactregion 42, which is fixedly attached to the insulating material 26 andin electrical contact with the associated pin 30. This may beaccomplished using a conductive epoxy or by depositing a thin layer ofindium or an indium alloy in the contact region of each membrane section28 and affecting a cold indium weld between the layer of insulatingmaterial 26 and the contact region 42 of the membrane section. Thesecond region, defined by the diagonal bar pattern, is the hinge region44 and is that segment of the membrane which flexs when the section issubjected to electrostatic forces. The third region is the imprintedregion 46 which is imprinted with a color contrasting to the color ofthe opaque fluid 16. For example, if the opaque fluid is white, theimprinted region would be black and vice versa. Obviously, othercontrasting color combinations including the use of fluorescent colorson the imprinted regions could also be used if so desired. To improvethe sharpness of the generated character, the hinge region 44 andcontact region 42 may be colored to blend in with the color of theopaque fluid. Alternatively, an opaque mask deposited on the insidesurface of the window could be used to occlude the hinge and contactregions of the sections. The surface of the membrane sections 28 may becon tinuous or porous. A porous membrane would permit fluid to flowthrough the membrane reducing its resistance to movement therebyincreasing the response time of display panel.

The operation of the display panel is as follows:

An electrostatic potential difference is established between thetransparent conductive coating 20 disposed over the inner surface of thecomposite window It) and the metal plate 24 by means of the source ofelectrical power supply, such as battery 38. Information indicative ofthe character to be displayed is input into the control logic 40 whichgenerates electrical signals communicated to the respective pins 30 onthe display panel. The pins in electrical contact with the membranesections 28, which form the input character, receive electrical signalhaving approximately the same magnitude and polarity as the potentialthe metal plate 24. The membrane sections forming the input characterassume the potential communicated to their respective pins and aresubjected to an electrostatic force urging the free imprinted region 46of the membrane sections towards the composite window 10. Under theinfluence of these electrostatic forces, the imprinted region of themembrane sections contact the transparent insulation material 22overlaying the conductive layer 20 and displaces the opaque fluid 16from therebetween. With the opaque fluid 16 so displaced, the im printedregion 46 of each membrane section in contact with the transparentinsulation material 22 becomes visible through the composite window It)and the input character is formed.

The remaining membrane sections receive signals from the control logicwhich have approximately the same magnitude and polarity as potential onthe conductive coating 20 and are held against the insulation material26 overlaying the metal plate 24 by electrostatic forces generatedbetween the membrane sections and the support substrate.

The electrical potentials required to displace the membrane sectionsagainst the window appear to be well within the output capabilities ofstate of the art solid state logic circuitry. Buffer or interfaceamplifiers to increase voltage or current levels are not required. Theforce of attraction per unit area between two parallel conductors can bederived from the energy stored in a capacitor. The electrostatic force Pis defined by the equation:

7 Where F,, the force per unit area between two parallel conductors(dynes/cm V the potential difference between the two parallel conductors(volts) .\"=the distance between the conductors (cm) and k thedielectric constant of the medium between the conductors (opaque fluid).

The dielectric constant of distilled water is 80, for glycol (C H O 38and furfural (C H O is 42. If we assume a dielectric constant lc=50,V=l0 volts x=x 0.()l cm, then the electrostatic force F dynes/cm whichis higher than a force experimentally known to be adequate to displacethe membrane section against the window. Therefore, a display panelbuilt in accordance with the disclosed principles will work.

While the electrical power supply has been illustrated as a DC source ofelectrical power and the operation of the panel discussed in terms of DCoperation, the display panel is also operable with alternating (AC)potentials. The requirement for AC operation is that all appliedpotentials including the signals to the membrane sections be changed ina synchronous manner so that the directions of the electrostatic forcesare unchanged. AC operation of the panel is desirable because itsignificantly reduces the electrolysis of the opaque fluid and increasesthe life of the panel.

An alternate embodiment of the composite base eliminating the pinsprotruding therethrough for electrical contact to the membrane sectionsis shown in FIGS. 3 and 4. In this embodiment, electrical conduc tors 48are deposited on an insulator substrate 50 made from glass or one of thecommercially available plastics. The conductors originate from a commonedge of the substrate, indicated as edge 52, and individually terminateat a location under one of the contact regions 42 of the associatedmembrane sections 28 (shown in phantom). The conductors 48 may be formedon the insulator substrate 50 using any of the methods well known in theart, such as vapor deposition, silk screening, etc. The conductors 48are overlaid with a thin film of insulating material 54 such as siliconmonoxide, except for the contact area 56 under the contact regions 42 ofthe membrane sections. The entire surface area of the support substrate50, again, with the exception of contact areas 56, is overlaid with aconductive film 58 which in turn is covered with insulator material 60.The membrane sections 28 are attached to the composite substrate 12 inthe desired positions and in electrical contact with the individualconductors 48 using any of the methods well known in the art. Themembrane sections may be attached to the composite substrate using aconductive epoxy or a thin layer of indium 62 over the area on thecomposite substrate 12, defined by the contact region 42 of eachmembrane section 28.

FIG. 9 illustrates an alternate configuration of the deflectablemembrane sections 28 forming the alpha numerical character. In thisconfiguration, the hinge region 72 is connected to the narrow ends ofthe imprinted region 74 and are substantially longer than they are wideto provide increased flexibility of the hinge. The hinge region may becolored to blend in with the color of the opaque fluid, as discussedwith reference to FIG. 2, or a mask having the same color as the opaquefluid may be imprinted on composite window 10 to occlude the hingeregion of the individual sections 28. The dashed lines 76 outline theareas on the composite window to be masked when this latter concept isemployed. The areas 78 (diagonal lines) indicate the areas to which aconductive epoxy or other bonding agent is applied to attach themembrane sections to the composite substrate 12. The operation of thedisplay panel is the same as discussed with reference to FIG. 1.

Although the display panel has been illustrated and described in FIGS. 1through 4 as having only a single alpha numerical character, it isobvious that the con cept can be extended to a multiple character panel,as shown in FIG. 5. The numbers used to identify the elementsillustrated in FIG. 5 are the same as used in FIGS. 1 through 4.

The multi character panel may be activated using any of the methodspresently available in the art including multiplex or matrix addresstechniques which require fewer leads between the display panel and thecontrol logic.

To multiplex a multi character panel, such as illustrated in FIG. 5, thestructure of the composite base may be made as shown on FIG. 6. In thisillustration the insulator substrate 50 and electrical conductors 48depicted in FIG. 3 are understood but not shown to simplify the drawing.The continuous conductive film 58 is segmented into a plurality ofelectrically isolated conductive islands 64 which may be individuallycharged by means of the logic control 66. The corresponding sections 28of each character on the multi character display are electricallyconnected in parallel to the logic control 66. The parallel electricalconnections of the corresponding sections may be made during thefabrication of the composite base 12 or be made externally, as shown.The operation of the multiplexed panel is as follows:

All of the islands 64 are initially electrically biased to the samepotential as the window, with the exception of the addressed islandassociated with the character, the position of whose membrane sectionsare to be set. The potential of the island being addressed is differentfrom that of the window to generate an electric field, as discussedrelative to FIG. 1. All the sections are then charged for a shortfraction of one clock cycle with a polarity opposite that of the window,i.e., the nominal potential applied to the conductive film on thecomposite base. Because the window and the nonaddressed islands have thesame electrical potential, the sections associated with the nonaddressedislands are attracted to the closest electrode, be it the window or thecomposite base. For the remainder of the clock cycle, the sections to bedisplaced towards the window remain at the potential of the addressedisland and the sections to be displaced against the composite base arebiased to the potential of the window. The sections at the windowpotential and associated with the nonaddressed islands will not movesince there is no field gradient between the window and the islands andthe sections will float electrically. Only the sections associated withthe addressed island will be attracted to the composite substrate. Thesections to be displaced against the window are charged to the potentialof the addressed island. The sections associated with the nonaddressedislands, as discussed above, are attracted to the nearest electrodesand, therefore, will retain their initial position,

either against the window or against the composite base. The sectionsassociated with the addressed island will be displaced against thewindow by electrostatic forces. By serially addressing the islandsassociated with each character on the panel, multiplexed operation maybe achieved. Logic controls for performing the required function andgenerating the required potentials are well within the state of the art.The location of the island being addressed can be determined from a pairof shift registers and the sections being driven in parallel from athird shift register device. The information indicative of thecharacters to be displayed is serially generated and loaded into thesection shift register device. When the section shift register isloaded, the island location shift registers are indexed to the nextsequential island location and both signals are simultaneously appliedto the panel.

For matrix operation, the structure of the composite substrate 12 may bemade as shown on FIG. 7. Again, the substrate 50 and conductors 48 arenot shown to simplify the drawing. The continuous conductive film 53 issegmented into a plurality of electrically isolated conductive stripes68 disposed in a plurality of rows which may be individually charged bya logic control 70. Each conductive stripe 68 being associated with onerow of characters on the multi character display panel. The charactersare divided according to columns and corresponding sections 28 in eachcharacter in each column are electrically connected in parallel. Theparallel electrical connection between corresponding sections in eachcolumn can be made during the fabrication of the composite substrate ormade externally as shown. Although only four characters are illustrated,two in each row, and two in each column, the concept is readily extendedto many rows and columns having many characters each.

The matrix operation of the display panel is similar to the multiplexoperation. Initially, all the rows 68 are charged to the potential ofthe window except the row containing the character whose sections are tobe charged. The information indicative of the sections to be displacedeither towards or away from the window is applied to the respectiveleads on the column containing character. Obviously, the characters inthe unaddressed columns will not change, and for the reasons discussedwith reference to multiplex configurations, only the sections in theaddressed column which are in the character in the activated row willchange. All other characters will remain unchanged. By sequentiallyswitching the activation of the individual rows and columns in apredeterminable order, each charac ter can be changed in accordance withthe signals generated by the logic control. It would be obvious to oneskilled in the art that the conductive stripes 68 could be disposedalong the columns and that the parallel connection of the like charactersections could be made along the rows without departing from the intentof the invention.

Having described the invention in terms of a panel having alphanumerical characters, it is recognized that other types of characterpatterns may be equally employed within the spirit of the invention.

One such character pattern is the conventional by 7 dot matrix in whichthe characters are formed by activating predetermined dots within thematrix. In this embodiment, the conductive film on the compositesubstrate is segmented into a plurality of electrically isolatedconductive stripes, one stripe for each row of dots in the pattern. Themembrane sections take the form of a plurality of parallel stripesangularly disposed to the conductive stripes; one parallel membranesection for each column in the dot pattern. The intersections betweenthe conductive stripes and the parallel membrane sections represent dotsin the pattern. From the prior discussion with reference to FIG. 6 and7, it is readily seen that by matrix addressing each row of conductivestripes and each column of membrane section in a predeterminablesequence the membrane sections at selected intersections can bedeflected into contact with the window to form the desired character.

In contrast to the multi character panels of FIGS. 5, 6 and 7, theprinciples of the electrostatic display panel may be embodied in asimple on/off type display having a predetermined message imprinted on asingle moveable membrane, such as shown in FIG. 8. It is understood thatthis type of display may have more than one moveable membrane and morethan one printed message. The operation of the display panel illustratedin FIG. 8 is the same as the character forming configuration discussedwith reference to FIGS. 1 and 2 and need not be repeated here. Oneskilled in the art will immediately conceive other embodiments based onthe disclosed principles of operation. The embodiments illustrated anddiscussed are merely to present the invention in several of its manyforms and are not intended to limit the scope of the invention.

What is claimed is:

1. An electrostatically actuated display panel comprising:

a composite base having at least one electrically conductive planarsurface and a thin surface layer of insulating material disposed oversaid conductive surface,

at least one electrically isolated, electrically conductive, flexiblemembrane section having a predetermined color, said membrane sectionhaving at one end a predetermined contact region fixedly attached tosaid composite base on the side having said layer of insulating materialand electrically isolated from said conductive surface, the opposite endof said at least one membrane section being free to move under theinfluence of electrostatic forces;

means for conducting an electrical charge to said at least one membranesection;

a composite planar window disposed parallel to said composite base andseparated therefrom by a predetermined distance slightly greater thanthe thickness of said membrane section, said composite window having athin layer of transparent electrically conductive material disposedalong the surface of I said window adjacent to said composite base;

means rigidly supporting said composite window from said composite baseand forming a peripherial fluid seal between said composite base andsaid composite window; and

a low conductivity high dielectric constant fluid, having a colorcontrasting to the color of said at least one membrane section, fillingin the space between said composite window, and said composite base,said fluidhaving an opacity sufficient to occlude viewing of said atleast one membrane section when said membrane section is disposedagainst the surface of said composite base.

2. The display panel of claim 1 wherein said at least one electricallyconductive flexible membrane section 1 1 comprises a thin sheet offlexible material having a length substantially longer than its width,said sheet of flexible material having said predetermined contact regionat one end, an imprinted region at the end opposite to said one end, anda hinge region disposed between said electrical contact region and saidimprinted region.

3. The display panel of claim 2 wherein only said imprinted region hassaid predetermined color, said contact region and said hinge regionhaving a color blending with the color of said opaque fluid.

4. The display panel of claim 2 wherein said thin sheet of flexiblematerial is porous to said opaque fluid.

5. The display panel of claim 4 wherein said thin sheet of flexiblematerial is nonconductive, said membrane section further includesconductive material embedded in said thin sheet of material to rendersaid material conductive.

6. The display panel of claim 4 wherein said thin sheet of flexiblematerial is nonconductive, said membrane sections further include a thinlayer of conductive material disposed over at least one surface of saidthin sheet.

7. The display panel of claim 4 wherein said thin sheet further includesa thin layer of insulator material disposed over surface of saidmembrane sections.

8. The display panel of claim 4 wherein said at least one membranesection is only one membrane section and said imprinted region has apredetermined message printed thereon.

9. The display panel of claim 4 wherein said at least one membranesection is a plurality of membrane sections electrically isolated fromeach other, each of said membrane sections having a message printed onsaid imprinted regions and wherein said means for conductingindependently conducts an electrical charge to each of said plurality ofmembrane sections.

10. The display panel of claim 2 wherein said at least one membranesection comprises a plurality of electrically isolated, electricallyconductive, flexible membrane sections disposed along the surface ofsaid composite base in at least one predetermined character formingpattern, and said means for conducting independently conducts anelectrical charge to each of said membrane sections.

11. The display panel of claim wherein said at least one predeterminedcharacter forming pattern comprises at least seven of said electricallyconductive flexible membrane sections arranged to form a block numeraleight.

12. The display panel of claim 11 wherein said character forming patternfurther includes an eighth electrically conductive flexible membranesection within the block numeral eight to form a period.

13. The display panel of claim 10 wherein said at least one characterforming pattern comprises a plurality of character forming patternslinearly disposed along a straight line.

14. The display panel of claim 10 wherein said at least one characterforming pattern comprises a plurality of character forming patternsdisposed in a multi line matrix.

15. The display panel of claim 1 wherein said composite window furtherincludes a thin. transparent layer of insulating material disposed overthe transparent conductive material.

16. The display panel of claim 15 wherein said layer of insulatingmaterial disposed along the surface of said composite window comprises aplurality of small isolated islands of insulating materialsystematically disposed over the transparent conductive material, andsaid layer of insulating material disposed along the surface of saidcomposite base also comprises a plurality of small isolated islands ofinsulating material systematically disposed along said conductivesurface, further wherein each island of insulating material disposedalong said composite window and said composite base are separated fromall adjacent islands by a distance sufficiently small to support saidflexible membrane sections in electrical isolation from said conductivematerial and said conductive surface respectively.

17. The display panel of claim 1 wherein said composite base includes arigid metal plate wherein said conductive surface is one surface of saidmetal plate.

18. The display panel of claim 17 wherein said metal plate furtherincludes a plurality of holes therethrough, one hole being disposed inthe contact region of each membrane section, said means for conductingan electrical charge to each membrane section is a plurality metalconductor wire having a diameter smaller than the diameter of said holesand a length substantially longer than the thickness of said metalplate, one of said metallic conductor wires concentrically disposed ineach of said holes with one end of said conductor wires flush with thesurface of said insulating material and in electrical contact with saidcontact regions and insulating material disposed between said metalplate and said conductor wires, electrically insulating said wires fromsaid metal plate.

19. The display panel of claim 1 wherein said composite base includes arigid plate of insulator material and said conductive surface is a thinlayer of conductive material disposed over the surface of said rigidplate of insulator material on the side adjacent to said compositewindow.

20. The display panel of claim 13 wherein said composite base includes abase substrate of insulator material and said conductive surfacecomprises a plurality of conductive islands disposed over the surface ofsaid base substrate, each of said conductive islands being associatedwith at least one of said character forming patterns.

21. The display panel of claim 14 wherein said composite base includes abase substrate of insulator material and said conductive surfacecomprises a plurality of conductive islands disposed over the surface ofsaid base substrate, each of said conductive islands being associatedwith at least one of said character forming patterns.

22. The display panel of claim 10 wherein:

said character forrnin g pattern is a multi element dot type matrixhaving a predetermined number of elements systematically arranged alongtwo axes angularly disposed to each other,

said composite base includes a base substrate of insulator material andsaid conductive surface comprises a plurality of electrically isolatedconductive stripes disposed parallel to one of said two axes, saidplurality of conductive stripes equal to the number of elements in saidmulti element matrix along the other of said two axes,

said membrane sections comprise a plurality of narrow membrane sectionsdisposed parallel to said other axis, said plurality of membranesections equal in number of elements in said multi element matrix alongsaid one axis.

23. The display panel of claim 1 wherein said predetermined distance isof the order of 0.01 centimeter.

24. The display panel of claim 1 wherein said opaque fluid comprises amixture of ethyl acetate and oil soluble dye.

25. An electrostatically actuated display panel system comprising:

a composite base having an electrically conductive planar surface and athin surface layer of insulating material disposed over said conductivesurface;

a plurality of thin electrically isolated electrically conductiveflexible membrane sections disposed along the surface of said compositebase having said insulating material in at least one predeterminedcharacter forming pattern, each of said membrane sections having alongone edge a predetermined contact region fixedly attached to saidcomposite base and an imprinted region at the opposite end having apredetermined color, each of said membrane electrically isolated fromsaid conductive surface;

means for independently conducting an electrical charge to each of saidmembrane sections;

a composite window disposed parallel to said composite substrate andseparated therefrom by a predetermined distance slightly greater thanthe thickness of said membrane sections, said composite window having athin layer of transparent electrically conductive material disposedalong the sur face of the composite adjacent to said compositesubstrate;

a peripheral support means rigidly positioning said composite windowwith respect to said composite substrate and providing a peripheralfluid seal therebetween;

a low conductivity, high dielectric constant fluid having a colorcontrasting to the color of said imprinted region, filling in the spacebetween said composite window and said composite substrate, said fluidhaving an opacity sufficient to occlude the' viewing of said imprintedregion when said membrane sections are disposed against the surface ofsaid composite substrate;

a source of electrical power having at least two outputs of differentelectrical potentials, one of said outputs providing electrical power tothe conductive surface of said composite base substrate, the otheroutput providing electrical power to the conductive material disposedalong the surface of said transparent window; and

control logic means electrically connected to the means for conductingan electrical charge to each of said membrane sections for generatingelectrical signals charging predetermined membrane sections in responseto input signals indicative of character to be generated.

26. The display panel system of claim wherein:

said source of electrical power is an AC source of electrical powerwherein the potential of said two outputs alternate at a predeterminedfrequency, and wherein the potential of the signals generated by saidcontrol logic means synchronously alternate with two outputs of the ACpower source to maintain the relationship between the potentials appliedto the conductive surface of said composite base and the conductivematerial disposed along the surface of said transparent window, andsignals applied to the membrane sections.

27. The display panel system of claim 28 wherein said membrane sectionsare porous to said opaque fluid.

28. The display panel system of claim 25 wherein said composite windowfurther includes a thin transparent layer of insulating materialdeposited over the transparent conductive material.

29. The display panel system of claim 28 wherein said layer ofinsulating material deposited along the surface of said composite windowcomprises a plurality of small isolated islands of insulating materialsystematically disposed over the transparent conductive material, andsaid layer of insulating material disposed along the surface of saidcomposite base also comprises a plurality of small isolated islands ofinsulating material systematically disposed along said conductivesurface, further, wherein each island of insulating material disposedalong said composite window and said composite base are separated fromall adjacent islands by a distance sufficiently small to support saidmembrane sections in electrical isolation from said conductive materialand said conductive surface respectively.

30. The display panel system of claim 25 wherein said at least onepredetermined character forming pattern comprises at least seven linearelectrically conductive flexible membrane sections arranged to form ablock numeral eight, and further includes an eighth electricallyconductive flexible membrane section within the block numeral eight toform a period.

31. The display panel of claim 25 wherein said at least one characterforming pattern comprises a plurality of character forming patternsdisposed along a straight line.

32. The display panel of claim 31 wherein the conductive planar surfaceof said composite base comprises a plurality of electrically isolatedconductive islands disposed along said straight line of characterforming patterns with at least one of said islands being disposed undereach of said patterns;

further, wherein corresponding membrane section in each of saidcharacter forming patterns are electrically connected in parallel tosaid control logic means; and

wherein said logic control means includes:

means for generating electrical signals indicative of the character tobe generated for each of said character forming patterns in apredetermined sequence; and

means for applying to each of said islands, one at a time, in said samepredetermined sequence and in synchronization said electrical signals,said one output from the source of electrical power while simultaneouslyapplying to all other islands, said other output from the source ofelectrical power.

33. The display panel system of claim 25 wherein said at least onecharacter forming pattern comprises a plurality of character formingpatterns systematically disposed along the surface of said compositebase in a multi line matrix of character forming patterns.

34. The display panel of claim 33 wherein the conductive planar surfaceof said compositevbase comprises a plurality of electrically isolatedconductive planar islands in a multi line matrix corresponding to themulti line matrix of character forming patterns, each of said islandsbeing associated with a corresponding character forming pattern;

further, wherein corresponding membrane sections in each of saidcharacter forming patterns are electrically connected in parallel tosaid control logic means; and

wherein said logic control means further includes:

means for generating electrical signals indicative of the character tobe generated for each of said character forming patterns in apredetermined sequence; and

means for applying to each of said islands, one at a time, in said samepredetermined sequence and in synchronization with said electricalsignals, said one output from the source of electrical power whilesimultaneously applying to all other islands said other output from thesource of electrical power,

35. The display panel system of claim 33 wherein said multi line matrixhas the character forming patterns disposed at the intersections of twointerlaced sets of parallel lines angularly disposed to each other;

said conductive planar surface of said composite base comprises aplurality of electrically isolated conductive stripes disposed parallelto one of said two sets of lines, one of said parallel stripescorresponding with the patterns lying along each line in said one set oflines;

further, wherein corresponding sections of each character formingpattern lying along each line of the other set of parallel lines areelectrically connected in parallel; and wherein said logic control meansfurther includes; means for generating electrical signals indicative ofthe characters to be generated for each character forming pattern in afirst predetermined sequence;

means for applying said electrical signals to the parallel connectedmembrane sections of the patterns lying along said other set of parallellines in a second predetermined sequence, said second predeterminedsequence applying said signals to the line of patterns containing thepattern in which the character is to be generated; and

means for applying to the conductive stripes, said one output from thesource of electrical power in a third predetermined sequence whilesimultaneously applying to all other stripes said other output fromsource of electrical power, said third predetermined sequence applyingsaid one output to the conductive stripe associated with the line of l6patterns having the pattern in which the character is to be generated.

36. The display panel of claim 35 wherein said two interlaced sets ofparallel lines are angularly disposed at right angles to each other.

37. The display panel system of claim 25 wherein:

said character forming pattern is a multi element dot type matrix havinga predetermined number of elements systematically arranged at theintersections of two sets of parallel lines angularly disposed to eachother;

said conductive planar surface of said composite base comprises aplurality of electrically isolated conductive stripes, each of saidplurality of conductive stripes corresponding to one line in one of saidtwo sets of parallel lines;

said membrane sections comprises a second plurality of narrow membranesections, each narrow membrane section corresponding to one line in theother of said two sets of parallel lines; and

said logic control means comprises:

means for generating in a predetermined sequence a first set ofelectrical signals indicative of the elements in the matrix to bedisplaced to form the desired character, said first predeterminedsequence of electrical signals being applied to the narrow membranesection containing the element to be displaced in a like sequence;

means for generating in a predetermined sequence a second set ofelectrical signals applied to said conductive stripes, said second setof signals applying to each conductive stripe an electrical signal having a potential approximately equal to potential of said one outputwhile simultaneously applying to all other conductive stripes said otheroutput from said source of electrical power, further, wherein said firstand said second set of electrical signals are synchronously generated toapply both sets of signals to each element in the matrix, in apredetermined order.

38. The display panel system of claim 37 wherein said multi line elementmatrix is a five by seven element array arranged in the form of aparallelogram.

1. An electrostatically actuated display panel comprising: a compositebase having at least one electrically conductive planar surface and athin surface layer of insulating material disposed over said conductivesurface, at least one electrically isolated, electrically conductive,flexible membrane section having a predetermined color, said membranesection having at one end a predetermined contact region fixedlyattached to said composite base on the side having said layer ofinsulating material and electrically isolated from said conductivesurface, the opposite end of said at least one membrane section beingfree to move under the influence of electrostatic forces; means forconducting an electrical charge to said at least one membrane section; acomposite planar window disposed parallel to said composite base andseparated therefrom by a predetermined distance slightly greater thanthe thickness of said membrane section, said composite window having athin layer of transparent electrically conductive material disposedalong the surface of said window adjacent to said composite base; meansrigidly supporting said composite window from said composite base andforming a peripherial fluid seal between said composite base and saidcomposite window; and a low conductivity higH dielectric constant fluid,having a color contrasting to the color of said at least one membranesection, filling in the space between said composite window, and saidcomposite base, said fluid having an opacity sufficient to occludeviewing of said at least one membrane section when said membrane sectionis disposed against the surface of said composite base.
 2. The displaypanel of claim 1 wherein said at least one electrically conductiveflexible membrane section comprises a thin sheet of flexible materialhaving a length substantially longer than its width, said sheet offlexible material having said predetermined contact region at one end,an imprinted region at the end opposite to said one end, and a hingeregion disposed between said electrical contact region and saidimprinted region.
 3. The display panel of claim 2 wherein only saidimprinted region has said predetermined color, said contact region andsaid hinge region having a color blending with the color of said opaquefluid.
 4. The display panel of claim 2 wherein said thin sheet offlexible material is porous to said opaque fluid.
 5. The display panelof claim 4 wherein said thin sheet of flexible material isnonconductive, said membrane section further includes conductivematerial embedded in said thin sheet of material to render said materialconductive.
 6. The display panel of claim 4 wherein said thin sheet offlexible material is nonconductive, said membrane sections furtherinclude a thin layer of conductive material disposed over at least onesurface of said thin sheet.
 7. The display panel of claim 4 wherein saidthin sheet further includes a thin layer of insulator material disposedover surface of said membrane sections.
 8. The display panel of claim 4wherein said at least one membrane section is only one membrane sectionand said imprinted region has a predetermined message printed thereon.9. The display panel of claim 4 wherein said at least one membranesection is a plurality of membrane sections electrically isolated fromeach other, each of said membrane sections having a message printed onsaid imprinted regions and wherein said means for conductingindependently conducts an electrical charge to each of said plurality ofmembrane sections.
 10. The display panel of claim 2 wherein said atleast one membrane section comprises a plurality of electricallyisolated, electrically conductive, flexible membrane sections disposedalong the surface of said composite base in at least one predeterminedcharacter forming pattern, and said means for conducting independentlyconducts an electrical charge to each of said membrane sections.
 11. Thedisplay panel of claim 10 wherein said at least one predeterminedcharacter forming pattern comprises at least seven of said electricallyconductive flexible membrane sections arranged to form a block numeraleight.
 12. The display panel of claim 11 wherein said character formingpattern further includes an eighth electrically conductive flexiblemembrane section within the block numeral eight to form a period. 13.The display panel of claim 10 wherein said at least one characterforming pattern comprises a plurality of character forming patternslinearly disposed along a straight line.
 14. The display panel of claim10 wherein said at least one character forming pattern comprises aplurality of character forming patterns disposed in a multi line matrix.15. The display panel of claim 1 wherein said composite window furtherincludes a thin, transparent layer of insulating material disposed overthe transparent conductive material.
 16. The display panel of claim 15wherein said layer of insulating material disposed along the surface ofsaid composite window comprises a plurality of small isolated islands ofinsulating material systematically disposed over the transparentconductive material, and said layer of insulating material disposedalong the surface of said composite base also comprises a plurality ofsmall isolatEd islands of insulating material systematically disposedalong said conductive surface, further wherein each island of insulatingmaterial disposed along said composite window and said composite baseare separated from all adjacent islands by a distance sufficiently smallto support said flexible membrane sections in electrical isolation fromsaid conductive material and said conductive surface respectively. 17.The display panel of claim 1 wherein said composite base includes arigid metal plate wherein said conductive surface is one surface of saidmetal plate.
 18. The display panel of claim 17 wherein said metal platefurther includes a plurality of holes therethrough, one hole beingdisposed in the contact region of each membrane section, said means forconducting an electrical charge to each membrane section is a pluralitymetal conductor wire having a diameter smaller than the diameter of saidholes and a length substantially longer than the thickness of said metalplate, one of said metallic conductor wires concentrically disposed ineach of said holes with one end of said conductor wires flush with thesurface of said insulating material and in electrical contact with saidcontact regions and insulating material disposed between said metalplate and said conductor wires, electrically insulating said wires fromsaid metal plate.
 19. The display panel of claim 1 wherein saidcomposite base includes a rigid plate of insulator material and saidconductive surface is a thin layer of conductive material disposed overthe surface of said rigid plate of insulator material on the sideadjacent to said composite window.
 20. The display panel of claim 13wherein said composite base includes a base substrate of insulatormaterial and said conductive surface comprises a plurality of conductiveislands disposed over the surface of said base substrate, each of saidconductive islands being associated with at least one of said characterforming patterns.
 21. The display panel of claim 14 wherein saidcomposite base includes a base substrate of insulator material and saidconductive surface comprises a plurality of conductive islands disposedover the surface of said base substrate, each of said conductive islandsbeing associated with at least one of said character forming patterns.22. The display panel of claim 10 wherein: said character formingpattern is a multi element dot type matrix having a predetermined numberof elements systematically arranged along two axes angularly disposed toeach other, said composite base includes a base substrate of insulatormaterial and said conductive surface comprises a plurality ofelectrically isolated conductive stripes disposed parallel to one ofsaid two axes, said plurality of conductive stripes equal to the numberof elements in said multi element matrix along the other of said twoaxes, said membrane sections comprise a plurality of narrow membranesections disposed parallel to said other axis, said plurality ofmembrane sections equal in number of elements in said multi elementmatrix along said one axis.
 23. The display panel of claim 1 whereinsaid predetermined distance is of the order of 0.01 centimeter.
 24. Thedisplay panel of claim 1 wherein said opaque fluid comprises a mixtureof ethyl acetate and oil soluble dye.
 25. An electrostatically actuateddisplay panel system comprising: a composite base having an electricallyconductive planar surface and a thin surface layer of insulatingmaterial disposed over said conductive surface; a plurality of thinelectrically isolated electrically conductive flexible membrane sectionsdisposed along the surface of said composite base having said insulatingmaterial in at least one predetermined character forming pattern, eachof said membrane sections having along one edge a predetermined contactregion fixedly attached to said composite base and an imprinted regionat the opposite end having a predetermined color, each of said membRaneelectrically isolated from said conductive surface; means forindependently conducting an electrical charge to each of said membranesections; a composite window disposed parallel to said compositesubstrate and separated therefrom by a predetermined distance slightlygreater than the thickness of said membrane sections, said compositewindow having a thin layer of transparent electrically conductivematerial disposed along the surface of the composite adjacent to saidcomposite substrate; a peripheral support means rigidly positioning saidcomposite window with respect to said composite substrate and providinga peripheral fluid seal therebetween; a low conductivity, highdielectric constant fluid having a color contrasting to the color ofsaid imprinted region, filling in the space between said compositewindow and said composite substrate, said fluid having an opacitysufficient to occlude the viewing of said imprinted region when saidmembrane sections are disposed against the surface of said compositesubstrate; a source of electrical power having at least two outputs ofdifferent electrical potentials, one of said outputs providingelectrical power to the conductive surface of said composite basesubstrate, the other output providing electrical power to the conductivematerial disposed along the surface of said transparent window; andcontrol logic means electrically connected to the means for conductingan electrical charge to each of said membrane sections for generatingelectrical signals charging predetermined membrane sections in responseto input signals indicative of character to be generated.
 26. Thedisplay panel system of claim 25 wherein: said source of electricalpower is an AC source of electrical power wherein the potential of saidtwo outputs alternate at a predetermined frequency, and wherein thepotential of the signals generated by said control logic meanssynchronously alternate with two outputs of the AC power source tomaintain the relationship between the potentials applied to theconductive surface of said composite base and the conductive materialdisposed along the surface of said transparent window, and signalsapplied to the membrane sections.
 27. The display panel system of claim25 wherein said membrane sections are porous to said opaque fluid. 28.The display panel system of claim 25 wherein said composite windowfurther includes a thin transparent layer of insulating materialdeposited over the transparent conductive material.
 29. The displaypanel system of claim 28 wherein said layer of insulating materialdeposited along the surface of said composite window comprises aplurality of small isolated islands of insulating materialsystematically disposed over the transparent conductive material, andsaid layer of insulating material disposed along the surface of saidcomposite base also comprises a plurality of small isolated islands ofinsulating material systematically disposed along said conductivesurface, further, wherein each island of insulating material disposedalong said composite window and said composite base are separated fromall adjacent islands by a distance sufficiently small to support saidmembrane sections in electrical isolation from said conductive materialand said conductive surface respectively.
 30. The display panel systemof claim 25 wherein said at least one predetermined character formingpattern comprises at least seven linear electrically conductive flexiblemembrane sections arranged to form a block numeral eight, and furtherincludes an eighth electrically conductive flexible membrane sectionwithin the block numeral eight to form a period.
 31. The display panelof claim 25 wherein said at least one character forming patterncomprises a plurality of character forming patterns disposed along astraight line.
 32. The display panel of claim 31 wherein the conductiveplanar surface of said composite base comprises a plurality ofelectrically isolaTed conductive islands disposed along said straightline of character forming patterns with at least one of said islandsbeing disposed under each of said patterns; further, whereincorresponding membrane section in each of said character formingpatterns are electrically connected in parallel to said control logicmeans; and wherein said logic control means includes: means forgenerating electrical signals indicative of the character to begenerated for each of said character forming patterns in a predeterminedsequence; and means for applying to each of said islands, one at a time,in said same predetermined sequence and in synchronization saidelectrical signals, said one output from the source of electrical powerwhile simultaneously applying to all other islands, said other outputfrom the source of electrical power.
 33. The display panel system ofclaim 25 wherein said at least one character forming pattern comprises aplurality of character forming patterns systematically disposed alongthe surface of said composite base in a multi line matrix of characterforming patterns.
 34. The display panel of claim 33 wherein theconductive planar surface of said composite base comprises a pluralityof electrically isolated conductive planar islands in a multi linematrix corresponding to the multi line matrix of character formingpatterns, each of said islands being associated with a correspondingcharacter forming pattern; further, wherein corresponding membranesections in each of said character forming patterns are electricallyconnected in parallel to said control logic means; and wherein saidlogic control means further includes: means for generating electricalsignals indicative of the character to be generated for each of saidcharacter forming patterns in a predetermined sequence; and means forapplying to each of said islands, one at a time, in said samepredetermined sequence and in synchronization with said electricalsignals, said one output from the source of electrical power whilesimultaneously applying to all other islands said other output from thesource of electrical power.
 35. The display panel system of claim 33wherein said multi line matrix has the character forming patternsdisposed at the intersections of two interlaced sets of parallel linesangularly disposed to each other; said conductive planar surface of saidcomposite base comprises a plurality of electrically isolated conductivestripes disposed parallel to one of said two sets of lines, one of saidparallel stripes corresponding with the patterns lying along each linein said one set of lines; further, wherein corresponding sections ofeach character forming pattern lying along each line of the other set ofparallel lines are electrically connected in parallel; and wherein saidlogic control means further includes; means for generating electricalsignals indicative of the characters to be generated for each characterforming pattern in a first predetermined sequence; means for applyingsaid electrical signals to the parallel connected membrane sections ofthe patterns lying along said other set of parallel lines in a secondpredetermined sequence, said second predetermined sequence applying saidsignals to the line of patterns containing the pattern in which thecharacter is to be generated; and means for applying to the conductivestripes, said one output from the source of electrical power in a thirdpredetermined sequence while simultaneously applying to all otherstripes said other output from source of electrical power, said thirdpredetermined sequence applying said one output to the conductive stripeassociated with the line of patterns having the pattern in which thecharacter is to be generated.
 36. The display panel of claim 35 whereinsaid two interlaced sets of parallel lines are angularly disposed atright angles to each other.
 37. The display panel system of claim 25wherein: said character foRming pattern is a multi element dot typematrix having a predetermined number of elements systematically arrangedat the intersections of two sets of parallel lines angularly disposed toeach other; said conductive planar surface of said composite basecomprises a plurality of electrically isolated conductive stripes, eachof said plurality of conductive stripes corresponding to one line in oneof said two sets of parallel lines; said membrane sections comprises asecond plurality of narrow membrane sections, each narrow membranesection corresponding to one line in the other of said two sets ofparallel lines; and said logic control means comprises: means forgenerating in a predetermined sequence a first set of electrical signalsindicative of the elements in the matrix to be displaced to form thedesired character, said first predetermined sequence of electricalsignals being applied to the narrow membrane section containing theelement to be displaced in a like sequence; means for generating in apredetermined sequence a second set of electrical signals applied tosaid conductive stripes, said second set of signals applying to eachconductive stripe an electrical signal having a potential approximatelyequal to potential of said one output while simultaneously applying toall other conductive stripes said other output from said source ofelectrical power, further, wherein said first and said second set ofelectrical signals are synchronously generated to apply both sets ofsignals to each element in the matrix, in a predetermined order.
 38. Thedisplay panel system of claim 37 wherein said multi line element matrixis a five by seven element array arranged in the form of aparallelogram.